qa_config: Remove exclusive storage flag from config
qa_config: Remove exclusive storage flag from config

Commit 6a0f22e added the ability to track the status of the cluster-wide
flag for exclusive storage. It did so in a way which modifies the
in-memory configuration dictionary. This patch changes the code to use a
plain global variable as a temporary solution until a configuration
object is added.

Signed-off-by: Michael Hanselmann <68b67885ff74281219b4a4be33cc20fd45078d7c@google.com>
Reviewed-by: Helga Velroyen <2d0126b1ec6f9ec5cbec4a7012aa14faeaef10f5@google.com>

dimara/ganeti,ganeti-github-testing/ganeti-test-1,apyrgio/ganeti,ganeti/ganeti,leshchevds/ganeti,grnet/snf-ganeti,mbakke/ganeti,ganeti/ganeti,grnet/snf-ganeti,bitemyapp/ganeti,mbakke/ganeti,leshchevds/ganeti,andir/ganeti,andir/ganeti,ganeti-github-testing/ganeti-test-1,apyrgio/snf-ganeti,yiannist/ganeti,leshchevds/ganeti,apyrgio/ganeti,andir/ganeti,apyrgio/snf-ganeti,dimara/ganeti,onponomarev/ganeti,ganeti/ganeti,mbakke/ganeti,onponomarev/ganeti,bitemyapp/ganeti,yiannist/ganeti,yiannist/ganeti